This invention relates to locks for security enclosures such as safes, strong boxes and the like. Such locks are mounted on the inside of the safes, and they are operated by means of handles or dials which are mounted on the outside of the safes and connected to said locks via spindles extending through the outer and inner walls of the safe and through the insulation therebetween. The spindles are usually fixed to cam drivers which engage and position lock cams that, in turn, cooperate with locking bolt assemblies to prevent the opening of the enclosures until the lock cam is moved to a position permitting the bolt to be moved. The movement of the spindles is controlled by a special key, or by the operation of a combination, or by insertion of a magnetic card, etc.
The components of such locks are supported on a bushing bolted to a mounting plate that attaches to the inner wall of the safe. Usually, the components are assembled at the time the lock is installed in the safe, being received over drive spindles which are mounted through holes in the safe walls to connect the dials or handles on the outside wall of the safe with the lock components mounted on the inner wall. With safes having heavy steel walls, it is not unusual to have slight misalignment problems between the spindle holes in the inner and outer walls. These alignment problems can cause the spindle to be canted in relation to the inner wall, i.e., not perpendicular to the surface of the inner wall; and this in turn makes it difficult to line up a cam driver or drive tumbler (fixed to the spindle) with other lock components fixed to the inner wall. This misalignment can cause tumbler skipping or dragging, can create stiffness in the movement of the lock components, and/or can result in unsatisfactory wear problems.
Further, when combination locks are used, the installer must assemble the components, e.g., tumbler wheels, spacing washers, retaining nuts, etc., with special care to assure that the tumblers, while being readily movable, are not too loose and that the movement of the dial feels smooth and consistent. Since each installer has his or her own sense of smoothness, similar locks from the same manufacturer may feel differently because assembled by different installers. In addition, the movement of such combination locks often loosens with wear and loses this needed smoothness and consistency.
We have developed a universal mounting structure which can be used with many different lock assemblies. The manufacture of locks for safes is simplified and made more economical by using this novel mounting structure. Lock components can be preassembled prior to installation in the safe, and the entire premounted assembly can be easily shimmed during installation to overcome spindle alignment problems. Also, use of this universal mount permits critical lock components, such as the tumbler wheel assemblies of combination locks, to be assembled prior to installation. Therefore, the smoothness and consistency of tumbler wheel assemblies can be tested and adjusted before installation, and the movement of such combination locks can be made uniform and not dependent upon the sensibilities of the installer.
Further, by virtue of this independent assembly feature of our invention, the security of the lock is increased. That is, since the tumbler wheel assembly is independent of the dial/spindle/driver mechanism, if the dial should be broken off and the spindle be punched out, the tumbler wheel assembly remains intact to prevent opening of the safe enclosure.